Cu(II)-Mediated Sulfonylation of (Hetero)arenes with TosMIC Using Monodentate Directing Groups.

Monodentate chelation-assisted direct ortho-C-H sulfonylation of (hetero)arenes using TosMIC as the novel sulfonylating reagent has been developed. A broad range of substrates, including indolines, indoles, 2-phenylpyridines, and others were well tolerated to afford the corresponding products in moderate to good yields. Mechanistic studies revealed that the sulfonyl radical might be involved. Inspired by the above discovery, preliminary para-C-H sulfonylation of naphthalene substrate was also successfully realized. The current protocol featured with cheap metal catalysis, good functional group compatibility, and operational convenience.

Simultaneously enhanced magnomechanical cooling and entanglement assisted by an auxiliary microwave cavity.

We propose a mechanism to simultaneously enhance quantum cooling and entanglement via coupling an auxiliary microwave cavity to a magnomechanical cavity. The auxiliary cavity acts as a dissipative cold reservoir that can efficiently cool multiple localized modes in the primary system via beam-splitter interactions, which enables us to obtain strong quantum cooling and entanglement. We analyze the stability of the system and determine the optimal parameter regime for cooling and entanglement under the auxiliary-microwave-cavity-assisted (AMCA) scheme. The maximum cooling enhancement rate of the magnon mode can reach 98.53%, which clearly reveals that the magnomechanical cooling is significantly improved in the presence of the AMCA. More importantly, the dual-mode entanglement of the system can also be significantly enhanced by AMCA in the full parameter region, where the initial magnon-phonon entanglement can be maximally enhanced by a factor of about 11. Another important result of the AMCA is that it also increases the robustness of the entanglement against temperature. Our approach provides a promising platform for the experimental realization of entanglement and quantum information processing based on cavity magnomechanics.

Mechanisms involved in the sequestration and resistance of cadmium for a plant-associated Pseudomonas strain.

Understanding Cd-resistant bacterial cadmium (Cd) resistance systems is crucial for improving microremediation in Cd-contaminated environments. However, these mechanisms are not fully understood in plant-associated bacteria. In the present study, we investigated the mechanisms underlying Cd sequestration and resistance in the strain AN-B15. These results showed that extracellular Cd sequestration by complexation in strain AN-B15 was primarily responsible for the removal of Cd from the solution. Transcriptome analyses have shown that the mechanisms of Cd resistance at the transcriptional level involve collaborative processes involving multiple metabolic pathways. The AN-B15 strain upregulated the expression of genes related to exopolymeric substance synthesis, metal transport, Fe-S cluster biogenesis, iron recruitment, reactive oxygen species oxidative stress defense, and DNA and protein repair to resist Cd-induced stress. Furthermore, inoculation with AN-B15 alleviated Cd-induced toxicity and reduced Cd uptake in the shoots of wheat seedlings, indicating its potential for remediation. Overall, the results improve our understanding of the mechanisms involved in Cd resistance in bacteria and thus have important implications for improving microremediation.

Resistance mechanisms and remediation potential of hexavalent chromium in Pseudomonas sp. strain AN-B15.

The understanding of bacterial resistance to hexavalent chromium [Cr(VI)] are crucial for the enhancement of Cr(VI)-polluted soil bioremediation. However, the mechanisms related to plant-associated bacteria remain largely unclear. In this study, we investigate the resistance mechanisms and remediation potential of Cr(VI) in a plant-associated strain, AN-B15. The results manifested that AN-B15 efficiently reduced Cr(VI) to soluble organo-Cr(III). Specifically, 84.3 % and 56.5 % of Cr(VI) was removed after 48 h in strain-inoculated solutions supplemented with 10 and 20 mg/L Cr(VI) concentrations, respectively. Transcriptome analyses revealed that multiple metabolic systems are responsible for Cr(VI) resistance at the transcriptional level. In response to Cr(VI) exposure, strain AN-B15 up-regulated the genes involved in central metabolism, providing the reducing power by which enzymes (ChrR and azoR) transformed Cr(VI) to Cr(III) in the cytoplasm. Genes involved in the alleviation of oxidative stress and DNA repair were significantly up-regulated to neutralize Cr(VI)-induced toxicity. Additionally, genes involved in organosulfur metabolism and certain ion transporters were up-regulated to counteract the starvation of sulfur, molybdate, iron, and manganese induced by Cr(VI) stress. Furthermore, a hydroponic culture experiment showed that toxicity and uptake of Cr(VI) by plants under Cr(VI) stress were reduced by strain AN-B15. Specifically, strain AN-B15 inoculation increased the fresh weights of the wheat root and shoot by 55.5 % and 18.8 %, respectively, under Cr(VI) stress (5 mg/L). The elucidation of bacterial resistance to Cr(VI) has an important implication for exploiting microorganism for the effective remediation of Cr(VI)-polluted soils.

Influencing factors of refractory anastomotic stenosis after laparoscopic intersphincteric resec-tion for rectal cancer and construction of nomogram prediction model / 中华消化外科杂志

Objective:To investigate the influencing factors of refractory anastomotic stenosis after laparoscopic intersphincteric resection (Ls-ISR) for rectal cancer and construction of nomogram prediction model.Methods:The retrospective case-control study was conducted. The clinicopatho-logical data of 495 patients who underwent Ls-ISR for rectal cancer in two medical centers, including 448 patients in Peking University First Hospital and 47 patients in Cancer Hospital Chinese Academy of Medical Sciences, from June 2012 to December 2021 were collected. There were 311 males and 184 females, aged 61 (range, 20-84)years. Observation indicators: (1) incidence of anastomotic stenosis; (2) influencing factors of refractory anastomotic stenosis after Ls-ISR; (3) construction and evaluation of nomogram prediction model for refractory anastomotic stenosis after Ls-ISR. Follow-up was conducted using outpatient examination and telephone interview to detect the incidence of postoperative anastomotic leakage and anastomotic stenosis up to August 2022. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test. Univariate and multivariate analyses were conducted using the Logistic regression model. Factors with P<0.10 in univariate analysis were included in multivariate analysis. The R software (3.6.3 version) was used to construct nomogram prediction model. The receiver operating characteristic (ROC) curve was drawn and the area under curve (AUC) was used to evaluate the efficacy of nomogram prediction model. Results:(1) Incidence of anastomotic stenosis. All 495 patients underwent Ls-ISR successfully, without conversion to laparotomy, and all patients were followed up for 47(range, 8-116)months. During the follow-up period, there were 458 patients without anas-tomotic stenosis, and 37 patients with anastomotic stenosis. Of the 37 patients, there were 15 cases with grade A anastomotic stenosis, 3 cases with grade B anastomotic stenosis and 19 cases with grade C anastomotic stenosis, including 22 cases being identified as the refractory anastomotic stenosis. Fifteen patients with grade A anastomotic stenosis were relieved after anal dilation treat-ment. Three patients with grade B anastomotic stenosis were improved after balloon dilation and endoscopic treatment. Nineteen patients with grade C anastomotic stenosis underwent permanent stoma. During the follow-up period, there were 42 cases with anastomotic leakage including 17 cases combined with refractory anastomotic stenosis, and 453 cases without anastomotic leakage including 5 cases with refractory anastomotic stenosis. There was a significant difference in the refractory anastomotic stenosis between patients with and without anastomotic leakage ( χ2=131.181, P<0.05). (2) Influencing factors of refractory anastomotic stenosis after Ls-ISR. Results of multivariate analysis showed that neoadjuvant therapy, distance from tumor to anal margin ≤4 cm, clinic N+ stage were independent risk factors of refractory anastomotic stenosis after Ls-ISR ( hazard ratio=7.297, 3.898, 2.672, 95% confidence interval as 2.870-18.550, 1.050-14.465, 1.064-6.712, P<0.05). (3) Construction and evaluation of nomogram prediction model for refractory anastomotic stenosis after Ls-ISR. Based on the results of multivariate analysis, neoadjuvant therapy, distance from tumor to anal margin and clinic N staging were included to constructed the nomogram prediction model for refractory anastomotic stenosis after Ls-ISR. Results of ROC curve showed the AUC of nomogram prediction model for refractory anastomotic stenosis after Ls-ISR was 0.739 (95% confidence interval as 0.646-0.833). Conclusions:Neoadjuvant therapy, distance from tumor to anal margin ≤4 cm, clinic N+ stage are independent risk factors of refractory anastomotic stenosis after Ls-ISR. Nomogram prediction model based on these factors can predict the incidence of refractory anastomotic stenosis after Ls-ISR.

Reconstruction of karyotypic evolution in Saccharum spontaneum species by comparative oligo-FISH mapping.

BACKGROUND: Karyotype dynamics driven by chromosomal rearrangements has long been considered as a fundamental question in the evolutionary genetics. Saccharum spontaneum, the most primitive and complex species in the genus Saccharum, has reportedly undergone at least two major chromosomal rearrangements, however, its karyotypic evolution remains unclear. RESULTS: In this study, four representative accessions, i.e., hypothetical diploid sugarcane ancestor (sorghum, x = 10), Sa. spontaneum Np-X (x = 10, tetraploid), 2012-46 (x = 9, hexaploid) and AP85-441 (x = 8, tetraploid), were selected for karyotype evolution studies. A set of oligonucleotide (oligo)-based barcode probes was developed based on the sorghum genome, which allowed universal identification of all chromosomes from sorghum and Sa. spontaneum. By comparative FISH assays, we reconstructed the karyotype evolutionary history and discovered that although chromosomal rearrangements resulted in greater variation in relative lengths of some chromosomes, all chromosomes maintained a conserved metacentric structure. Additionally, we found that the barcode oligo probe was not applicable for chromosome identification in both Sa. robustum and Sa. officinarum species, suggesting that sorghum is more distantly related to Sa. robustum and Sa. officinarum compared with Sa. spontaneum species. CONCLUSIONS: Our study demonstrated that the barcode oligo-FISH is an efficient tool for chromosome identification and karyotyping research, and expanded our understanding of the karyotypic and chromosomal evolution in the genus Saccharum.

Genome sequence of Gossypium anomalum facilitates interspecific introgression breeding.

Crop wild relatives are an important reservoir of natural biodiversity. However, incorporating wild genetic diversity into breeding programs is often hampered by reproductive barriers and a lack of accurate genomic information. We assembled a high-quality, accurately centromere-anchored genome of Gossypium anomalum, a stress-tolerant wild cotton species. We provided a strategy to discover and transfer agronomically valuable genes from wild diploid species to tetraploid cotton cultivars. With a (Gossypium hirsutum × G. anomalum)2 hexaploid as a bridge parent, we developed a set of 74 diploid chromosome segment substitution lines (CSSLs) of the wild cotton species G. anomalum in the G. hirsutum background. This set of CSSLs included 70 homozygous substitutions and four heterozygous substitutions, and it collectively contained about 72.22% of the G. anomalum genome. Twenty-four quantitative trait loci associated with plant height, yield, and fiber qualities were detected on 15 substitution segments. Integrating the reference genome with agronomic trait evaluation of the CSSLs enabled location and cloning of two G. anomalum genes that encode peroxiredoxin and putative callose synthase 8, respectively, conferring drought tolerance and improving fiber strength. We have demonstrated the power of a high-quality wild-species reference genome for identifying agronomically valuable alleles to facilitate interspecific introgression breeding in crops.

Computational Investigation and Histopathological Validation of Interaction Between Stent Graft and Aorta in Retrograde Type A Dissection After TEVAR in Canine Models.

PURPOSE: Retrograde type A dissection (RTAD) after thoracic endovascular aortic repair (TEVAR) has been a major drawback of endovascular treatment. To our knowledge, no studies have simulated and validated aortic injuries caused by stent grafts (SGs) in animal models. Therefore, the aim of this study was to evaluate and quantify the SG-aorta interaction through computational simulations and to investigate the underlying mechanism through histopathological examinations. METHODS: Two custom-made Fabulous® (DiNovA Meditech, Hang Zhou, China) SGs were implanted in 2 canine aortas with a 5-mm difference in the distance in landing locations. The aortic geometries were extracted from RTAD and non-RTAD cases. A computational SG model was assembled based on the implanted SG using the software Pro-ENGINEER Wildfire 5.0 (PTC Corporation, Needham, Mass). TEVAR simulations were performed 7 times for each canine model using Abaqus software (Providence, RI, USA), and the maximum aortic stress (MAS) was calculated and compared among the groups. Three months after SG implantation, the canine aortas were harvested, and were examined using hematoxylin and eosin staining and Elastica Van Gieson (EVG) staining to evaluate histopathological changes. RESULTS: In the computational models for both canines, MAS was observed at the proximal bare stent (PBS) at aortic greater curve. The PBS generated higher stress toward the aortic wall than other SG parts did. Moreover, the MAS was significantly higher in canine No.1 than in canine No.2 (0.415±0.210 versus 0.200±0.160 MPa) (p<0.01). Notably, in canine No.1, an RTAD developed at the MAS segment, and histopathological examinations of the segment showed an intimal flap, a false lumen, elastin changes, and medial necrosis. RTAD was not observed in canine No.2. In both SG-covered aortas, medial necrosis, elastic fiber stretching, and inflammatory infiltration were seen. CONCLUSION: The characteristic MAS distribution remained at the location where the apex of the PBS interacted with the aortic wall at greater curve. RTAD histopathological examinations showed intimal damage and medial necrosis at the proximal landing zone, at the same MAS location in computational simulations. The in vivo results were consistent with the computational simulations, suggesting the MAS at greater curve may cause RTAD, and the potential application of computational simulation in the mechanism study of RTAD.

Mechanisms controlling the transformation of and resistance to mercury(II) for a plant-associated Pseudomonas sp. strain, AN-B15.

Bioremediation using mercury (Hg)-volatilizing and immobilizing bacteria is an eco-friendly and cost-effective strategy for Hg-polluted farmland. However, the mechanisms controlling the transformation of and resistance to Hg(II) by these bacteria remain unknown. In this study, a plant-associated Pseudomonas sp. strain, AN-B15 was isolated and determined to effectively remove Hg(II) under both nutrient-poor and nutrient-rich conditions via volatilization by transforming Hg(II) to Hg(0) and immobilization by transforming Hg(II) to mercury sulfide and Hg-sulfhydryl. Genome and transcriptome analyses revealed that the molecular mechanisms involved in Hg(II) resistance in AN-B15 were a collaborative process involving multiple metabolic systems at the transcriptional level. Under Hg(II) stress, AN-B15 upregulated genes involved in the mer operon and producing the reducing power to rapidly volatilize Hg(II), thereby decreasing its toxicity. Hydroponic culture experiments also revealed that inoculation with strain AN-B15 alleviated Hg-induced toxicity and reduced the uptake of Hg(II) in the roots of wheat seedlings, as explained by the volatilization and immobilization of Hg(II) and plant growth-promoting traits of AN-B15. Overall, the results from the in vitro assays provided vital information that are essential for understanding the mechanism of Hg(II) resistance in plant-associated bacteria, which can also be applied for the bioremediation of Hg-contamination in future.

Chromosome Painting Provides Insights Into the Genome Structure and Evolution of Sugarcane.

The genus Saccharum is composed of species with high polyploidy and highly varied chromosome numbers, laying a challenge for uncovering its genomic structure and evolution. We developed a chromosome 2 painting (CP2) probe by designing oligonucleotides covering chromosome 2 of Saccharum spontaneum (2n = 8x = 64). Fluorescence in situ hybridization (FISH) using this CP2 probe revealed six types of ploidies from twenty S. spontaneum clones, including 6x, 8x, 10x, 11x, 12x, and 13x clones. The finding of S. spontaneum clones with uneven of ploid suggested that certain S. spontaneum clones come from hybridization. It renews our knowledge that S. spontaneum is derived from autopolyploidization. Combined with a S. spontaneum-specific probe, chromosome 2-derived chromosome or fragments from either S. spontaneum or Saccharum officinarum can be identified in sugarcane modern cultivars. We revealed unexpected high level of interspecific recombination from introgressive S. spontaneum chromosomes (>50.0%) in cultivars ROC22 and ZZ1, indicating frequent chromosome exchange in cultivars. Intriguingly, we observed interspecific recombination recurring among either homoeologous or non-homoeologous chromosomes in sugarcane cultivars. These results demonstrated that chromosome painting FISH is a powerful tool in the genome dissection of sugarcane and provide new insights into the genome structure and evolution of the complex genus Saccharum.

Megabase-scale presence-absence variation with Tripsacum origin was under selection during maize domestication and adaptation.

BACKGROUND: Structural variants (SVs) significantly drive genome diversity and environmental adaptation for diverse species. Unlike the prevalent small SVs (< kilobase-scale) in higher eukaryotes, large-size SVs rarely exist in the genome, but they function as one of the key evolutionary forces for speciation and adaptation. RESULTS: In this study, we discover and characterize several megabase-scale presence-absence variations (PAVs) in the maize genome. Surprisingly, we identify a 3.2 Mb PAV fragment that shows high integrity and is present as complete presence or absence in the natural diversity panel. This PAV is embedded within the nucleolus organizer region (NOR), where the suppressed recombination is found to maintain the PAV against the evolutionary variation. Interestingly, by analyzing the sequence of this PAV, we not only reveal the domestication trace from teosinte to modern maize, but also the footprints of its origin from Tripsacum, shedding light on a previously unknown contribution from Tripsacum to the speciation of Zea species. The functional consequence of the Tripsacum segment migration is also investigated, and environmental fitness conferred by the PAV may explain the whole segment as a selection target during maize domestication and improvement. CONCLUSIONS: These findings provide a novel perspective that Tripsacum contributes to Zea speciation, and also instantiate a strategy for evolutionary and functional analysis of the "fossil" structure variations during genome evolution and speciation.

Characterization of a Saccharum spontaneum with a basic chromosome number of x = 10 provides new insights on genome evolution in genus Saccharum.

KEY MESSAGE: A novel tetraploid S. spontaneum with basic chromosome x = 10 was discovered, providing us insights in the origin and evolution in Saccharum species. Sugarcane (Saccharum spp., Poaceae) is a leading crop for sugar production providing 80% of the world's sugar. However, the genetic and genomic complexities of this crop such as its high polyploidy level and highly variable chromosome numbers have significantly hindered the studies in deciphering the genomic structure and evolution of sugarcane. Here, we developed the first set of oligonucleotide (oligo)-based probes based on the S. spontaneum genome (x = 8), which can be used to simultaneously distinguish each of the 64 chromosomes of octaploid S. spontaneum SES208 (2n = 8x = 64) through fluorescence in situ hybridization (FISH). By comparative FISH assay, we confirmed the chromosomal rearrangements of S. spontaneum (x = 8) and S. officinarum (2n = 8x = 80), the main contributors of modern sugarcane cultivars. In addition, we examined a S. spontaneum accession, Np-X, with 2n = 40 chromosomes, and we found that it was a tetraploid with the unusual basic chromosome number of x = 10. Assays at the cytological and DNA levels demonstrated its close relationship with S. spontaneum with basic chromosome number x = 8 (the most common accessions in S. spontaneum), confirming its S. spontaneum identity. Population genetic structure and phylogenetic relationship analyses between Np-X and 64 S. spontaneum accessions revealed that Np-X belongs to the ancient Pan-Malaysia group, indicating a close relationship to S. spontaneum with basic chromosome number of x = 8. This finding of a tetraploid S. spontaneum with basic chromosome number of x = 10 suggested a parallel evolution path of genomes and polyploid series in S. spontaneum with different basic chromosome numbers.

Homocysteine might increase the risk of recurrence in patients presenting with primary cerebral infarction.

PURPOSE: Although hyperhomocysteinemia (Hhcy) is a risk factor for cerebral infarction, its effect on recurrent cerebral infarction is less-defined. We aimed to investigate the association of Hhcy and increased risk of recurrent cerebral infarct. MATERIALS AND METHODS: From 2011 to 2013, we recruited 231 primary cerebral infarct patients that were divided to a Hhcy group (n = 105) and a control group (n = 126) according to plasma homocysteinemia (Hcy) levels exceeding 15 µmol/L. In this prospective study, risk factors such as gender, age, blood lipid and glucose levels, history of diabetes, high blood pressure, smoking habits and plasma Hhcy levels were determined. A three-year follow-up compared differences in cerebral infarction recurrence rates. Statistical analyses identified whether plasma Hhcy levels were an independent risk factor for recurrent cerebral infarction. RESULTS: Triglyceride and low-density lipoprotein (LDL) levels in the Hhcy group were significantly higher than controls, and cerebral infarct recurrence rates in the Hhcy group exceeded control subject rates through the three-year follow-up (p = .021, p = .036 and p = .025). Cox proportional hazards modeling showed that elevated Hhcy levels (hazard ratio [HR] = 3.062, p < .001), increased age (HR = 1.069, p < .01), circulating triglyceride levels (HR = 1.686, p = .048), and relative National Institutes of Health Stroke (NIHSS) score (HR = 1.068, p = .016) were risk factors for recurrent cerebral infarction. CONCLUSIONS: Level of Hhcy was a risk factor for recurrent cerebral infarction. Further, particular demographic and clinical outcomes including age, relative NIHSS scores, and circulating triglyceride levels were markedly associated with the occurrence of cerebral infarction.

Comprehensively Characterizing the Cytological Features of Saccharum spontaneum by the Development of a Complete Set of Chromosome-Specific Oligo Probes.

Chromosome-specific identification is a powerful technique in the study of genome structure and evolution. However, there is no reliable cytogenetic marker to unambiguously identify each of the chromosomes in sugarcane (Saccharum spp., Poaceae), which has a complex genome with a high level of ploidy and heterozygosity. In this study, we developed a set of oligonucleotide (oligo)-based probes through bioinformatic design and massive synthetization. These probes produced a clear and bright single signal in each of the chromosomes and their eight homologous chromosomes in the ancient species Saccharum spontaneum (2n = 8x = 64). Thus, they can be used as reliable markers to robustly label each of the chromosomes in S. spontaneum. We then obtained the karyotype data and established a nomenclature based on chromosomal sizes for the eight chromosomes of the octoploid S. spontaneum. In addition, we also found that the 45S and 5S rDNAs demonstrated high copy number variations among different homologous chromosomes, indicating a rapid evolution of the highly repeated sequence after polyploidization. Our fluorescence in situ hybridization (FISH) assay also demonstrated that these probes could be used as cross-species markers between or within the genera of Sorghum and Saccharum. By comparing FISH analyses, we discovered that several chromosome rearrangement events occurred in S. spontaneum, which might have contributed to the basic chromosome number reduction from 10 in sorghum to 8 in sugarcane. Consistent identification of individual chromosomes makes molecular cytogenetic study possible in sugarcane and will facilitate fine chromosomal structure and karyotype evolution of the genus Saccharum.

Computational investigation of interaction between stent graft and aorta in retrograde type A dissection after thoracic endovascular aortic repair for type B aortic dissection.

OBJECTIVE: Retrograde type A dissection (RTAD) after thoracic endovascular aortic repair (TEVAR) has been a major drawback of endovascular treatment. To our knowledge, no studies have evaluated aortic injuries caused by stent grafts (SGs). Therefore, the aim of this study was to evaluate and to quantify the SG-aorta interaction and to analyze the risk factors for injury through computational simulation. METHODS: The aortic geometry was extracted from an RTAD case. Five SG models were assembled based on Valiant and Talent (Medtronic Vascular, Santa Rosa, Calif) SGs, and modifications were made to the original SG design by adding and removing the connecting bar. TEVAR simulations were performed seven times for each SG model with 0% and 15% oversizing ratio (OSR), and the maximum aortic stress (MAS) was calculated and compared within the groups. RESULTS: In all TEVAR models, MAS was seen at the proximal bare stent (PBS). The PBS in the Valiant and Talent SGs generated higher stress toward the aortic wall than other SG parts did. MAS was significantly higher for the 15% OSR (0.54 ± 0.07 MPa) than for the 0% OSR (1.32 ± 0.74 MPa) in 172.5-mm Valiant models. MAS was significantly higher in the Talent with connecting bar SG model (0.73 ± 0.24 MPa) than in the Talent without connecting bar SG model (0.51 ± 0.11 MPa). MAS was significantly higher in the Valiant with connecting bar SG model (0.82 ± 0.29 MPa) than in the Valiant without connecting bar SG model (0.54 ± 0.07 MPa). MAS was not significantly different in models with 172.5-mm and 140-mm Valiant SG implantations with 0% OSR (0.54 ± 0.07 MPa vs 0.60 ± 0.12 MPa) and 15% OSR (1.32 ± 0.74 MPa vs 1.12 ± 0.33 MPa). CONCLUSIONS: The characteristic MAS distribution remained at the location where the apexes of the PBS interacted with the aortic wall at its greater curve. Both higher OSR and the presence of a connecting bar can significantly increase the MAS after SG implantation. Moreover, the chronic MAS at the PBS area may injure the aortic wall, causing RTAD.

Isolation and characterization of centromeric repetitive DNA sequences in Saccharum spontaneum.

Sugarcane (Saccharum hybrids spp.) is the most important sugar crop that accounts for ~75% of the world's sugar production. Recently, a whole-genome sequencing project was launched on the wild species S. spontaneum. To obtain information on the DNA composition of the repeat-enriched region of the centromere, we conducted a genome-wide analysis of the DNA sequences associated with CenH3 (a mutant of histone H3 located in eukaryote centromeres) using chromatin immunoprecipitation followed by sequencing (ChIP-seq) method. We demonstrate that the centromeres contain mainly SCEN-like single satellite repeat (Ss1) and several Ty3/gypsy retrotransposon-related repeats (Ss166, Ss51, and Ss68). Ss1 dominates in the centromeric regions and spans up to 500 kb. In contrast, the Ty3/gypsy retrotransposon-related repeats are either clustered spanning over a short range, or dispersed in the centromere regions. Interestingly, Ss1 exhibits a chromosome-specific enrichment in the wild species S. spontaneum and S. robustum, but not in the domesticated species S. officinarum and modern sugarcane cultivars. This finding suggests an autopolyploid genome identity of S. spontaneum with a high level of homology among its eight sub-genomes. We also conducted a genome-wide survey of the repetitive DNAs in S. spontaneum following a similarity-based sequence clustering strategy. These results provide insight into the composition of sugarcane genome as well as the genome assembly of S. spontaneum.

Chromosome Nomenclature and Cytological Characterization of Sacred Lotus.

Sacred lotus is a basal eudicot plant that has been cultivated in Asia for over 7,000 years for its agricultural, ornamental, religious, and medicinal importance. A notable characteristic of lotus is the seed longevity. Extensive endeavors have been devoted to dissect its genome assembly, including the variety China Antique, which germinated from a 1,300-year-old seed. Here, cytogenetic markers representing the 10 largest megascaffolds, which constitute approximately 70% of the lotus genome assembly, were developed. These 10 megascaffolds were then anchored to the corresponding lotus chromosomes by fluorescence in situ hybridization using these cytogenetic markers, and a set of chromosome-specific cytogenetic markers that could unambiguously identify each of the 8 chromosomes was generated. Karyotyping was conducted, and a nomenclature based on chromosomal length was established for the 8 chromosomes of China Antique. Comparative karyotyping revealed relatively conserved chromosomal structures between China Antique and 3 modern cultivars. Interestingly, significant variations in the copy number of 45S rDNA were detected between China Antique and modern cultivars. Our results provide a comprehensive view on the chromosomal structure of sacred lotus and will facilitate further studies and the genome assembly of lotus.

Research Progress on Chimeric Antigen Receptor T Cells-Review / 中国实验血液学杂志

As more and more clinical trials about chimeric antigen receptor T cells (CAR-T) have been carried out successfully, the CAR-T are getting well-known. Thanks for genetic engineering, CAR-T has the tumor special antigen expressed on the surface. CAR-T therapy is the adoptive immunotheraphy for rapidly advancing tumors. This technology has made a great progress in both blood malignancies and solid tumor. However, CAR-T also meet many difficulties in the way of development. This review discusses the clinical application, challenges and developing trend of CAR-T.

[Formation Mechanism of the Disinfection By-product 1, 1-Dichloroacetone in Drinking Water].

A novel method using methyl tertiary butyl ether (MTBE) as extractant and 1,2-dibromopropane as internal standard for the determination of the disinfection by-producs 1,1-dichloroacetone (DCAce) by gas chromatography mass spectrometry (GC-MS) was described. The formation process of DCAce and its influencing factors were discussed with L-leucine as the precursor during the chloramination process. The results indicated that the DCAce production increased with the increase of chloramine dosage when the chloramine addition was in the range of 5-30 mg · L(-1). The DCAce amount produced under alkaline condition was higher than those produced under the neutral and acidic conditions, and the DCAce amount reduced with the increase of pH value. Temperature was another important factor that affected the DCAce formation from methylamine especially in the range of 15-35°C , and the higher the temperature, the more the DCAce produced. The formation process of DCAce from L-leucine by chloramine consisted of a series of complicated reactions, including substitution, oxidation, bond breaking, amino diazotization, reduction and so on, and eventually DCAce was formed.

Amifostine used in the treatment of patients with myelodysplastic syndrome / 中国实验血液学杂志

The study was aimed to investigate the curative effects and adverse effects of amifostine in the treatment of patients with myelodysplastic syndrome (MDS). Amifostine (AMF) was used alone (4/12) or combined with recombinant human erythropoietin (rh-EPO) (8/12) in 12 MDS patients. The therapeutic regimen was adopted with AMF 0.4 g/day for 5 days, then took a break of 2 days and then went on for 3 weeks consecutively, that was reputed as one treatment cycle. rh-EPO 6 000 U was used for 3 days per week. The results showed that 12 patients all attained hematological improvement in peripheral blood. 11 cases showed major effective response rate (91.7%), while 1 case showed minor response rate (8.3%). The effective response rate of hemoglobin, leukocytes and platelets was 100%, 75% and 58.3% respectively. The intervals of red cell transfusions (RCT) in 2 cases living on red cell transfusion before AMF treatment were prolonged after AMF treatments, and the amount of each RCT was decreased obviously. The side effect was usually discomfort of digestive system, but all patients can endure. In conclusion, Amifostine is a potential drug in the treatment of MDS patients with safety especially to those elder patients who often suffered from other multiple organ disfunctions, and the curative effect will be improved by more treatment cycles.